The present invention relates to snow and ice load control devices for roofs and in particular to an assembly attachable to roofs susceptible to ice build-up for protecting protruding plumbing vent pipes, chimneys, HVAC appliances, gutters and the like mounted to project from the roof from damage due to snow and ice slides.
Roofs found in geographic locales that experience snow and ice conditions are constructed to withstand the added weight of typical snow and ice that can buildup on the roofs during the winter months. For some roofs, the weight of the snow/ice can build over time to damage the building interior from leaks that arise from ice dams and other conditions. For some roofs, sheets of the snow/ice can slide from the roofs and injure nearby persons or damage property affixed to the roof or in close proximity to the building eaves. Metal and fiberglass panel roofs are particularly susceptible to snow/ice slides.
Metal roofs, such as typically made from steel panels, are frequently found on outbuildings at farms, ranches and in commercial warehouse and office sites. Metal panel roofing is also used with a variety of residential building applications. Such roofing offers durability, cost and installation advantages. Depending upon the climate and especially for sites subject to relatively heavy annual snow falls, the roofs are periodically susceptible to snow removal via snow slides, especially for relatively steeply pitched roofs of 5×12 or greater pitches. The steeper pitch enhances the gravitational effect on the snow/ice upon exposure to sun and wind and the natural inclination of the snow/ice to detach and slide from the roof. Snow/ice loading is thereby alleviated but at the expense of possible damage to structures in the slide path either on the roof or ground.
The panels can be used with less steeply pitched roofs but associated framing may have to be increased depending upon typical snow/ice loading. Less steeply pitched roofs are particularly common on large buildings. For example, buildings that are 50′ wide by 100′ long may have a 4×12 pitch and buildings 70′ wide by 150′ and longer may have a 3×12 pitch.
The framing design of buildings and roofs found in snow country typically position chimneys, plumbing vents and other vertically protruding structures relatively high up the roof and close to the peak. Because any vertical protuberance is subject to contact with any snow or ice sliding from the roof a higher mounting limits the volume and weight of snow/ice contacting the appliance during slide or avalanche conditions. It is not however always possible to place the protruding appliance near the peak. Consequently, when large heavy weight slides occur, the protruding appliances can be exposed to high shear stresses that can dislodge, detach or crush the appliance and/or tear a large hole in the roof.
Depending upon the severity of any damage, leaks can occur at the appliance or in the vicinity of the booted flashings typically used in association with the appliance. The leaks may or may not be readily detected, but will eventually become apparent when water from subsequent snow melt or rain enters the building and drains through lower lying ceilings, walls, fixtures etc.
A variety of devices have been developed to retain snow to the roof to prevent unwanted slide conditions. Such devices provide surfaces designed to hold the snow to the roof and assume the snow will melt without producing slide or avalanche conditions.
Other devices have been developed to shear and breakup the sliding snow and ice during slide conditions to protect associated rain gutters. Such devices are designed with relatively shallow height profiles and merely shear the snow/ice slide close to the roof (i.e. 3-4 inches). These devices are typically positioned near the roof edges to breakup the slide front to reduce stresses on gutter systems supported from the roof edges. U.S. Pat. Nos. 2,129,833 and 5,044,130 disclose two of such devices.
As noted from the patent disclosures, multiples of the foregoing devices are typically mounted in a patterned placement between the pitched metal panel seams of the roof being protected, such as in rows and columns. One or more devices can be mounted in each seam space at desired distances from the roof edge. Although the shearing devices may reduce the size and mass of a sliding sheet of ice into multiple layers prior to striking any attached gutter, the upper layer of each sheet of sliding snow/ice can still encounter vertical appliances such as vent pipes and chimneys. The shearing forces placed on the protruding structures can damage the structures, roof and/or any associated scals or flashings.
The ice and snow diverters of the present invention were developed to provide assemblies specifically intended for mounting upstream of plumbing vent pipes, chimneys, antennas, HVAC structures that protrude through or mount to a roof. The diverters are constructed to mount upstream of each desired protuberance to (1) vertically shear the full height of any snow/ice slide and (2) laterally divert the sheared pieces away from the sides of any downstream vent pipe, chimney or the like.
The diverter assemblies particularly include a V-shaped diverter plate designed to vertically project above normal snow/ice depths and any downstream protruding structure(s) to protect the protruding structure. Accessory wing pieces can be added to the diverter webs to enhance the lateral and vertical displacement forces of the diverter.
The diverter assemblies of the invention include serrated stabilizing shear arms constructed to withstand heavy weight. Fasteners and seals secured to a base plate and associated spreader arm(s) secure the diverter assemblies directly to the roof framing members (e.g. trusses and purlins) to prevent damage to the underlying roof panel.